Cow Vetch (Vicia cracca)
A European import cultivated for fodder, Cow Vetch tends to be found wherever livestock is nearby. The vines twine through other less decorative weeds, and the beautiful blue-purple flowers light up the edges of fields. This patch grew in a sunny meadow near Cranberry, where it was blooming in the middle of June.
Gray describes the genus and the species:
Calyx 5-cleft or 5-toothed, the 2 upper teeth often shorter, or the lowest longer. Wings of the corolla adhering to the middle of the keel. Stamens more or less diadelphous (9 and 1); the orifice of the tube oblique. Style filiform, hairy all round or only on the back at the apex. Pod flat, 2-valved, 2-several-seeded. Seeds globular. Cotyledons very thick, remaining under ground in germination. Herbs, mostly climbing more or less by the tendril at the end of the pinnate leaves. Stipules half-sagittate. Flowers or peduncles axillary. (The classical Latin name.)
V. cracca L. Appressed-pubescent; leaflets 8-24, oblong-lanceolate, strongly mucronate; racemes densely many-flowered, 1-sided; flowers blue, turning purple (rarely white), 1-1.2 cm. long, reflexed; calyx-teeth shorter than the tube. Borders of thickets or in fields, Nfd. to N. J., w. to Ky., la., and Minn. June- Aug. (Eu.)